Everything was placed exactly he wanted it for the graduation ceremony.A. while B. when C

问题补充：

Everything was placed exactly he wanted it for the graduation ceremony.

A. while

B. when

C. where

D. though

答案：

A. while

B. when

(答案→)C. where

D. though

解析：句意：一切东西都已准确地放在了他想要举行毕业典礼的地方。while当……时候；when当……时候；where哪里；though尽管。由where引导地点状语从句。根据句意故选C。